Prone position during venovenous extracorporeal membrane oxygenation: survival analysis needed for a time-dependent intervention

Akram M. Zaaqoq, Adrian G. Barnett, Silver Heinsar, Matthew J. Griffee, Graeme MacLaren, Jeffrey P. Jacobs, Jacky Y. Suen, Gianluigi Li Bassi, John F. Fraser, Heidi J. Dalton, Giles J. Peek on behalf of the COVID-19 Critical Care Consortium Crit Care https://doi.org/10.1186/s13054-022-03923-3

To the Editor, We read with great interest the paper of Giani and colleagues titled "Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a pooled individual patient data analysis" published in the critical care journal [1]. We are surprised that their meta-analysis failed to show a survival benefit for prone positioning during venovenous extracorporeal membrane oxygenation (VV ECMO). We would like to postulate that this was due to the limitation of the statistical methods.